Klingberg (undisclosed) will miss Toronto's games against Chicago on Friday and Pittsburgh on Saturday, per David Alter of Sports Illustrated.
There's no timetable for Klingberg's return, but it's not a great sign that he's already been ruled out for the Maple Leafs' next two contests. Klingberg has five assists in 14 games this season. He was last in the lineup Nov. 11 versus Vancouver.